O sistema radicular do cafeeiro nos principais tipos de solo do estado de São Paulo

Franco, Coaraci M.; Inforzato, Romeu

doi:10.1590/S0006-87051946000900001

Resumo

A new method for the study of the root system of the coffee plant Coffea arabica L. is described. The method consists in excavating a ditch along a row of four plants, 15 cm apart from the trunks. Blocks of soil 30 cm square and varying thickness, depending on the depth from which they were taken, were removed so as to include a complete cross section of the root system. The first three layers were 10 cm thick; the next two layers, 20 cm; the remaining layers (variable in number), 30 cm thick. The roots from each block were washed, air dried and weighed. The data obtained were used to draw the excavation maps as represented in graphics, I, IV, VII, X and XIII. On theses maps each dot represents 0.1 g of roots. A formula is given to estimate the weight of the whole root system, from the data thus obtained. The method just described was used to study the root system of the coffee tree in four different types of soil of the State of São Paulo, Brazil. It is pointed out that the study of the root distribution based on weight alone might lead one to erroneous conclusions, since the first layers contain heavy non-absorbing roots whereas many active roots, light in weight, are located in deeper layers. A much better idea about the root distribution in the soil was obtained by drawing the excavation map on a black cloth in true seale, and then spreading the roots removed from each block soil inside the corresponding place in the map. The pictures of this arrangement are reproduced in fig. IV, V, VI, VII and VIII. The best root distribution was found in the soil "terra-roxa misturada" in the Campinas county (fig. IV). In this soil the roots extend beyond 2.5 m depth and are very' well distributed through the soil. The poorest root distribution was found in the soil "terra-roxa legítima" in the Eibeirão Preto county (fig. V). In this soil the roots are mostly confined to the superficial layers. A study of the soil profiles w r here the trees were growing offered an explanation for the configuration of the root systems; as obtained by the last method. Diagrams of the profiles are given in the text.

SUMMARY

A new method for the study of the root system of the coffee plant Coffea arabica L. is described. The method consists in excavating a ditch along a row of four plants, 15 cm apart from the trunks. Blocks of soil 30 cm square and varying thickness, depending on the depth from which they were taken, were removed so as to include a complete cross section of the root system. The first three layers were 10 cm thick; the next two layers, 20 cm; the remaining layers (variable in number), 30 cm thick.

The roots from each block were washed, air dried and weighed. The data obtained were used to draw the excavation maps as represented in graphics, I, IV, VII, X and XIII. On theses maps each dot represents 0.1 g of roots.

A formula is given to estimate the weight of the whole root system, from the data thus obtained.

The method just described was used to study the root system of the coffee tree in four different types of soil of the State of São Paulo, Brazil. It is pointed out that the study of the root distribution based on weight alone might lead one to erroneous conclusions, since the first layers contain heavy non-absorbing roots whereas many active roots, light in weight, are located in deeper layers.

A much better idea about the root distribution in the soil was obtained by drawing the excavation map on a black cloth in true seale, and then spreading the roots removed from each block soil inside the corresponding place in the map. The pictures of this arrangement are reproduced in fig. IV, V, VI, VII and VIII.

The best root distribution was found in the soil "terra-roxa misturada" in the Campinas county (fig. IV). In this soil the roots extend beyond 2.5 m depth and are very' well distributed through the soil.

The poorest root distribution was found in the soil "terra-roxa legítima" in the Eibeirão Preto county (fig. V). In this soil the roots are mostly confined to the superficial layers.

A study of the soil profiles w^rhere the trees were growing offered an explanation for the configuration of the root systems; as obtained by the last method. Diagrams of the profiles are given in the text.

Texto completo disponível apenas em PDF.

Full text available only in PDF format.

AGRADECIMENTOS

Os autores expressam aqui os seus sinceros agradecimentos ao Sr. Luiz O. T. Mendes, a quem devem, na sua maior parte, a elaboração do método para o cálculo do pêso total do sistema radicular, ao Sr. J. E. de Paiva Neto, chefe da Secção de Agrogeologia, por se ter encarregado dos estudos referentes aos solos e ao Sr. J. Castro Mendes, pela execução dos trabalhosos gráficos dos sistemas radiculares.

LITERATURA CITADA

1. Beckley, V. A. Observations of coffee ini Kenya. Pt. I, Chlorosis and die-back in coffee. Empire Jour. Exp. Agric. 3: 203-209. 1935.
2. Dafert, F. W. e Toledo Braga. Sôbre as substâncias minerais do cafeeiro. B. Relação de peso das partes singulares do cafeeiro. Relatório Secret. Agric. Com. Obr. Publ. São Paulo, 1892: 20-23. 1917.
3. Guiscafré-Arrilaga, J. and. L. A. Gomez. Studies of the root system of Coffea arabica L. I. Environment conditions affecting the distribution of coffee roots in Coloso clay. Jour. Agric. Univ. Puerto Rico 22: 227-262. 1938.
4. Guiscafré-Arrilaga, J. and L. A. Gomez. Studies of the root sistem of Coffea arabica L. III. Growth and distribution in Catalina clay soil. Jour. Dept. Agric. Puerte Rico. 24: 109-117. 1940.
5. Guiscafré-Arrilaga, J. and L. A. Gomez. Studies of the root system of Coffea arabica L. III. Growth and 'distribution of roots of 21-old trees in Catalina clay soil. Jour. Agric. Univ. Puerto Rico. 26: 34-39. 1942.
6. Nutman, F. J. The root-system of Coffea arabica L. I. Root.system in typical soils of British East Africa. Emp. Jour. Exp. Agric. 1: 271-284. 1933.
7. Nutman, F. J. The root-system of Coffea arabica II. The effect of somme soil conditions in modifying the normal root-system. Emp. Agric. 1: 285-296. 1933.
8. Nutman, F. J. The root-system of Coffea arabica III. The spacial distribution of the absorbing area of the root. Emp. Jour. Agric. 2: 293-302. 1934.
9. Trench, A. D. Preliminary observations on coffee roots in Kenya. Kenya Dept. Agric. Bull. n.° 2 pp 1-10. 1934.